Black Cotton Soil of Deccan Lava Plateau

In India Black cotton soil spread over Maharashtra, western parts of Madhya Pradesh, parts of Andhra Pradesh, parts of Gujarat, some parts of Tamil Nadu and Deccan Lava Plateau. Among these the black cotton soils of Deccan Lava Plateau are discussed here.

Most of black-cotton soils of India are spread across the Deccan Lava Plateau, the Malwa Plateau, and interior Gujarat, where there is both moderate rainfall and underlying basaltic rock. Because of their high clay content, black soils develop wide cracks during the dry season, but their iron-rich granular structure makes them resistant to wind and water erosion. They are also highly moisture-retentive, thus responding well to irrigation.

The soil in the Deccan plateau is made up of black basalt
soil. This type of soil is rich in humus. In addition to iron content they
contain fairly high quantities of lime, magnesia and alumina.

Such texture and composition of soil are formed
due to volcanic action of Deccan region. These igneous rocks break down in to
the black soils rendering fertility to them. They commonly known as the black
cotton soil because it is best suited for the cultivation of cotton.

In the most of cases those screens got to be: - broken, when placed into the natural clay, rocky shelves, stumped sand, etc. that’s why those screens recognized as self-sacrificial ones, - or moved together with displaced soil represented by weak geological deposits, which are a majority in urban and agricultural areas.

Here is only way to enhance shock absorbing effect to provide thickness of the screens at 0.5 m and depth of placement by 6 to 9 meters. The screens have to be made of rocky masonry walls or by massive concrete injection. Well known examples are fenced monasteries and castles stays for hundreds of years after earthquakes among disappearing and restored cities. Those “fences” are made of the rocks or bricks with thickness enough to resist to the artillery and depth to prevent tunneling under by the enemies. Seismic Star is an invention registered after four years of experts evaluations and three times successful applications. Thousands of men hours are compressed into our software to compute angles between screens shaped into the star trenched around protected structure or along of it for linear ones. The initial data is required to be listed by: - Shape or plan of the building or structure with the contour's dimensions. - Geological type of the soil into the depth of at 1 m to 3 m. - Required level of shock absorption (> 50%; between 25% and 50% and at 25%). - Expected earthquake magnitude known for certain area or country.

Following to the steps of instruction on computer’s screen results in the radius of Seismic Star, length of each side of the Star’s “beam” and topography of damaged soil from both sides of the Star’s screens. The depth of placement is 1 m and thickness of the screens could be any.

Printed images are shown on website www.seismicstar.com > “Seismic Star Brochure > pages 6,7.” On the pages 8 and 9 are shown results of the standard experiments without screen, with a screen as a circle and with a screen as a Seismic Star. The width of the screen depends on a trench machine excavation applies.

Technically speaking, computing gives exact angle between Star’s beams equal to the angle of the soil’ natural bulk distribution (this is an angle of the soil lump strewed from the top). Only in this case the particle of the soil strikes the surface of the screen and kicks back under the same angle, which results in lowest possible impact energy.

When angle of the force strike’ direction is deviate by 1 grad from the angle of trenched screen, then sin 1 grad is 0.01745. For instance, the earthquake force strikes by 10, 000 m tons x 0.01745 become 175 m. tons. On a practice there is no impact on building foundation at all, but soil from both sides of screens is crumbled and ready to attenuate next impact. Our software guarantees at 0 grad of deviation with protection from mistake on a job side by up to 11 grad.